U.S. patent application number 12/821332 was filed with the patent office on 2010-12-30 for filter device and projection type display apparatus using the same.
This patent application is currently assigned to PANASONIC CORPORATION. Invention is credited to Masaya Yamamoto.
Application Number | 20100328620 12/821332 |
Document ID | / |
Family ID | 43380340 |
Filed Date | 2010-12-30 |
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United States Patent
Application |
20100328620 |
Kind Code |
A1 |
Yamamoto; Masaya |
December 30, 2010 |
FILTER DEVICE AND PROJECTION TYPE DISPLAY APPARATUS USING THE
SAME
Abstract
A filter device includes: a filter unit including a housing in
which a roll filter stretched between a feeding shaft and a take-up
shaft is housed, the housing including, between the two shafts, an
opening for exposing a part of the filter; a filter installation
detection sensor for detecting installation of the filter unit; a
filter winding driving unit for taking up or rewinding the
installed filter; and a control unit for controlling operations of
the filter winding driving unit based on a detection signal from
the filter installation detection sensor. When the control unit
determines based on the detection signal from the filter
installation detection sensor that the filter is installed, the
control unit causes the filter winding driving unit to rewind the
filter by a predetermined amount and determines whether the filter
is new or not based on the rewinding. By detecting filter
replacement, information on the replaced filter can be reset.
Inventors: |
Yamamoto; Masaya; (Osaka,
JP) |
Correspondence
Address: |
HAMRE, SCHUMANN, MUELLER & LARSON P.C.
P.O. BOX 2902
MINNEAPOLIS
MN
55402-0902
US
|
Assignee: |
PANASONIC CORPORATION
Osaka
JP
|
Family ID: |
43380340 |
Appl. No.: |
12/821332 |
Filed: |
June 23, 2010 |
Current U.S.
Class: |
353/57 ;
96/429 |
Current CPC
Class: |
B01D 46/18 20130101;
G03B 21/16 20130101 |
Class at
Publication: |
353/57 ;
96/429 |
International
Class: |
G03B 21/16 20060101
G03B021/16; B01D 46/18 20060101 B01D046/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2009 |
JP |
2009-150625 |
Claims
1. A filter device comprising: a filter unit including a housing in
which a roll filter stretched between a feeding shaft and a take-up
shaft is housed, the housing including, between the two shafts, an
opening for exposing a part of the filter; a filter installation
detection sensor for detecting installation of the filter unit; a
filter winding driving unit for taking up or rewinding the
installed filter; and a control unit for controlling operations of
the filter winding driving unit based on a detection signal from
the filter installation detection sensor, wherein when the control
unit determines based on the detection signal from the filter
installation detection sensor that the filter is installed, the
control unit causes the filter winding driving unit to rewind the
filter by a predetermined amount and determines whether the filter
is new or not based on the operation of the rewinding.
2. The filter device according to claim 1, further comprising a
sensor for detecting rewinding of the filter performed by the
filter winding driving unit, wherein when the sensor does not
output a signal corresponding to detection of rewinding of the
filter for a certain period of time during the rewinding of the
filter by the predetermined amount, the control unit determines
that the filter is new.
3. The filter device according to claim 1, wherein when the control
unit determines that the filter is new, the control unit resets
information on the filter.
4. The filter device according to claim 1, wherein the control unit
obtains the detection signals from the filter installation
detection sensor over a plurality of times and when all of the
detection signals indicate that the filter is installed, the
control unit determines that the filter is installed.
5. The filter device according to claim 1, wherein when the control
unit determines based on the detection signal from the filter
installation detection sensor that the filter is not installed, the
control unit turns on a filter detachment flag, and when the
detection signal from the filter installation detection sensor
indicates that the filter is installed while the filter detachment
flag is on, the control unit determines that the filter is
installed.
6. The filter device according to claim 1, wherein after
determining that the filter is installed, the control unit causes
the filter winding driving unit to rewind the filter by a
predetermined amount after a lapse of predetermined time.
7. The filter device according to claim 1, further comprising a
starting end detection portion for detecting a starting end of the
filter along with the rewinding of the filter, wherein when the
starting end detection portion cannot detect the starting end of
the filter during the rewinding of the filter by a predetermined
amount, the control unit causes the filter winding driving unit to
take up the filter by the predetermined amount.
8. A projection type display apparatus comprising: a light source
unit; an image forming unit for forming an image by modulating
light from the light source unit; a projection optical system for
magnifying and projecting the formed image; a housing in which the
light source unit, the image forming unit and the projection
optical system are housed; an inlet and an outlet provided on the
housing; a blower unit for taking in air through the inlet or
letting out air through the outlet; and the filter device according
to claim 1 disposed at the inlet.
Description
BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a filter device using a
detachable roll filter unit and a projection type display apparatus
using the filter device.
[0003] 2. Description of Related Art
[0004] Projection type display apparatuses, such as a projector,
have been used in a variety of circumstances, home-theater,
commercial uses and so on. Projection type display apparatuses
include image display elements such as a liquid crystal panel and a
DMD (digital mirror device), and magnify and project an optical
image formed by concentrating strong light from a light source,
such as a lamp, onto the image display elements and modulating the
concentrated light in response to an input image signal. The image
display elements subjected to strong light, the light source
itself, the apparatus power supply, etc. could be damaged by heat
unless they are cooled adequately. For this reason, cooling fans
that provide a strong cooling effect generally are used in
projection type display apparatuses so as to blow air into the
apparatuses.
[0005] However, when a flow of air is produced by an air blow from
a cooling fan, dust in the air enters the apparatus, so that it is
necessary to remove the dust by providing the air intake with a
filter. However, when the dust accumulates on the filter, the
cooling effect drops. Therefore, many projection type display
apparatuses use detachable roll filters.
[0006] In a case where a detachable roll filter is used, the
cooling effect can be kept constant by taking up the filter when a
predetermined amount of dust accumulates on the filter. However,
since the length of the filter that can be taken up is fixed, the
filter needs replacing when it is taken up entirely.
[0007] After replacing the filter, it is necessary to reset
information on the replaced filter stored in the projection type
display apparatus. Specifically, the information includes the
take-up amount, estimated replacement time, an error and the like.
By resetting these kinds of information, the time over which the
new filter can be used can be estimated precisely.
[0008] Conventionally, after replacing a filter, the information on
the replaced filter has been reset by a user pressing a button for
resetting the filter information or selecting reset from a guidance
menu displayed by the projection type display apparatus. However,
when a user forgets to reset the information after replacing the
filter, the time over which the replacing filter can be used cannot
be estimated precisely.
[0009] As a measure directed to this problem, JP 2006-145053 A
discloses a system in which a serial number is read at regular
intervals from an IC tag attached to a filter and the filter
information is reset automatically when the serial number changes.
In this system, when the serial number read from the IC tag
changes, the system determines that the filter is replaced and
resets the information on the replaced filter. However, even when
the replacing filter is not new, the system resets the information
on the replaced filter.
[0010] Furthermore, the system is not configured to use a rolled
filter and it cannot be said that the system is suited for using a
rolled filter.
SUMMARY OF THE INVENTION
[0011] With the foregoing in mind, it is an object of the present
invention to provide a filter device capable of accurately
resetting filter information at the time of replacing a detachable
roll filter unit and a projection type display apparatus using the
filter device.
[0012] To solve the above-described problem, the filter unit of the
present invention includes: a filter unit including a housing in
which a roll filter stretched between a feeding shaft and a take-up
shaft is housed, the housing including, between the two shafts, an
opening for exposing a part of the filter; a filter installation
detection sensor for detecting installation of the filter unit; a
filter winding driving unit for taking up or rewinding the
installed filter; and a control unit for controlling operations of
the filter winding driving unit based on a detection signal from
the filter installation detection sensor. When the control unit
determines based on the detection signal from the filter
installation detection sensor that the filter is installed, the
control unit causes the filter winding driving unit to rewind the
filter by a predetermined amount and determines whether the filter
is new or not based on the rewinding.
[0013] According to the filter device of the present invention,
filter replacement is detected with certainty and filter
information is reset automatically. Therefore, the user can avoid
spending his time and effort in resetting the filter
information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a cross-sectional view showing an overall planer
configuration of a projection type display apparatus according to
one embodiment of the present invention.
[0015] FIG. 2 is a diagram showing a basic configuration of a
filter unit.
[0016] FIG. 3 is a diagram showing a configuration of a filter
device.
[0017] FIG. 4 is a block diagram showing a configuration of a
control system of the filter device according to one embodiment of
the present invention.
[0018] FIG. 5 is a flowchart showing an exemplary operation of the
control system for detecting the installed state of a filter.
[0019] FIG. 6 is a flowchart showing an exemplary operation for
determining whether to reset filter information or not.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The filter device of the present invention, having the basic
structure as described above, also can have improved configurations
as follows.
[0021] That is, the filter device of the present invention further
may include a sensor for detecting rewinding of the filter
performed by the filter winding driving unit, and when the sensor
does not output a signal corresponding to detection of rewinding of
the filter for a certain period of time during the rewinding of the
filter by the predetermined amount, the control unit may determine
that the filter is new.
[0022] Further, when the control unit determines that the filter is
new, the control unit may reset information on the filter.
[0023] Further, the control unit may obtain the detection signals
from the filter installation detection sensor over a plurality of
times and when all of the detection signals indicate that the
filter is installed, the control unit may determine that the filter
is installed.
[0024] Further, when the control unit determines based on the
detection signal from the filter installation detection sensor that
the filter is not installed, the control unit may turn on a filter
detachment flag, and when the detection signal from the filter
installation detection sensor indicates that the filter is
installed while the filter detachment flag is on, the control unit
may determine that the filter is installed.
[0025] Further, after determining that the filter is installed, the
control unit may cause the filter winding driving unit to rewind
the filter by a predetermined amount after a lapse of predetermined
time.
[0026] Further, the filter device of the present invention further
may include a starting end detection portion for detecting a
starting end of the filter along with the rewinding of the filter,
and when the starting end detection portion cannot detect the
starting end of the filter during the rewinding of the filter by a
predetermined amount, the control unit may cause the filter winding
driving unit to take up the filter by the predetermined amount.
[0027] The projection type display apparatus of the present
invention may include: a light source unit; an image forming unit
for forming an image by modulating light from the light source
unit; a projection optical system for magnifying and projecting the
formed image; a housing in which the light source unit, the image
forming unit and the projection optical system are housed; an inlet
and an outlet provided on the housing; a blower unit for taking in
air through the inlet and letting out air through the outlet; and
the filter device having any of the above-described configurations
disposed at the inlet.
Embodiment
[0028] Hereinafter, a Projection Type Display Apparatus According
to One Embodiment of the present invention will be described with
reference to the drawings. FIG. 1 is a cross-sectional view showing
the overall planar configuration of the projection type display
apparatus. One of the features of a filter device adopted in this
projection type display apparatus is that the filter device is
configured to reset filter information accurately at the time of
replacing a detachable roll filter unit. Therefore, the optical
system is not limited to one with a particular configuration and
the optical system illustrated in the present embodiment is a
typical optical system. Thus, in the following description, the
optical system will be explained only briefly.
[0029] In FIG. 1, light emitted by a lamp 1 as a light source is
reflected by a reflection mirror 2 frontwards, and enters an
optical unit 3. The incident light is separated into red, green and
blue colored light beams through dichroic mirrors 4 and 5 and total
reflection mirrors 6, 7 and 8.
[0030] The intensity of the separated light beams of the respective
colors is modulated by liquid crystal light bulbs 9R, 9G and 9B as
image display elements based on an external input signal (not
shown). These light beams are combined on one optical path by a
combine prism 11 including dichroic reflection films 10R and 10B,
and then the combined light beam enters a projection lens 12. The
projection lens 12 is designed to magnify images of the liquid
crystal light bulbs 9R, 9G and 9B and to project them on a screen
(not shown) placed in front of the apparatus.
[0031] An air intake fan 14 provided adjacent to the optical unit 3
introduces outside air (air with a relatively low temperature) into
the apparatus through a housing air intake 16 provided on a side
surface of a housing 15. The outside air taken in by the air intake
fan 14 is guided to an air intake duct 19 through a filter 18 (FIG.
2) in a filter unit 17 and is guided to an optical unit duct 20 in
intimate contact with a blowoff opening of the fan.
[0032] The optical unit duct 20 is provided with red, green and
blue apertures (not shown) at the positions respectively
corresponding to the bottom of the liquid crystal light bulbs 9R,
9G and 9B described above. The air issued from these apertures
takes away heat from the liquid crystal light bulbs 9R, 9G and 9B
and then is let out by an exhaust fan 21. During this process, the
air to be let out also takes away heat from the lamp 1, mechanical
components in the vicinity of the lamp 1, and a power supply unit
22.
[0033] In such a cooling process, external dust taken in together
with outside air could adhere to the periphery of the liquid
crystal panel and to the light source unit, and may cause problems
such as early deterioration of luminance and color unevenness in
projected images as a result. In order to prevent these problems,
the filter unit 17 is provided to face the housing air intake
16.
[0034] A control unit 23 has the function of controlling operations
of the filter unit 17 as a part of the functions of controlling
overall operations of the projection type display apparatus. A
detection output from a sensor for gathering data for controlling
operations of the filter unit 17 is inputted to the control unit
23, and the control unit 23 controls the filter unit 17 on the
basis of the sensor output.
[0035] Next, the structure of the filter unit 17 will be described
with reference to FIG. 2. The filter unit 17 has a detachable roll
filter configuration and includes a filter feeding shaft 25 and a
filter take-up shaft 26 in a small housing 24. The filter 18 is
stretched between the two shafts. The small housing 24 includes,
between the two shafts, an opening 27 for allowing air from the
housing air intake 16 of the projection type display apparatus to
flow in. Further, a rotation pulse detection rotary shaft 28 is
disposed between the filter feeding shaft 25 and the filter take-up
shaft 26. The rotation pulse detection rotary shaft 28 is
positioned on the path over which the filter 18 is taken up or
rewound and is pressed against the filter 18, allowing it to rotate
as the filter 18 is taken up or rewound. A filter installation
detection protrusion 29 used in detecting installation of the
filter unit 17 further is provided in the small housing 24.
[0036] FIG. 3 is a diagram showing a configuration of a filter
device 30 disposed in the projection type display apparatus. The
figure shows a state in which the filter unit 17 is installed on
the filter device 30. The filter device 30 includes a take-up motor
31 for providing constant-speed driving power, a drive shaft 32 for
transmitting the driving power from the motor 31, a motor power
transmission gear 33 for transmitting the power from the drive
shaft 32 and a forward/reverse switching gear 34 for switching
between the normal and reverse rotations in the take-up
direction.
[0037] Furthermore, normal rotation power transmission gears 35, 36
for transmitting power during the normal rotation and a normal
rotation gear 37 that is rotated by the power transmitted by the
normal rotation power transmission gears 35, 36 are provided. The
filter take-up shaft 26 of the filter unit 17 shown in FIG. 2
engages with the normal rotation gear 37 and takes up the filter 18
as the normal rotation gear 37 rotates. Further, reverse rotation
power transmission gears 38, 39 for transmitting power during the
reverse rotation and a reverse rotation gear 40 that is rotated by
the power transmitted by the reverse rotation power transmission
gears 38, 39 are provided. The filter feeding shaft 25 of the
filter unit 17 engages with the reverse rotation gear 40 and
rewinds the filter 18 as the reverse rotation gear 40 rotates.
[0038] Further, a rotation detection gear 41 that rotates through a
link with the rotation pulse detection rotary shaft 28 of the
filter unit 17 and a photosensor 42 for generating a pulse by
detecting projections and depressions of the rotation detection
gear 41 are provided. Further, a filter installation detection
sensor 43 for determining the presence or absence of the filter
installation detection protrusion 29 of the filter unit 17 is
provided. Detection signals from the photosensor 42 and the filter
installation detection sensor 43 are supplied to the control unit
23.
[0039] Next, the operation at the time of installing the filter
unit 17 to the filter device 30 will be described. The filter unit
17 shown in FIG. 2 is detachable, and when it is installed on the
filter device 30 shown in FIG. 3, the filter feeding shaft 25 and
the reverse rotation gear 40, the filter take-up shaft 26 and the
normal rotation gear 37, and the rotation pulse detection rotary
shaft 28 and the rotation detection gear 41 are coupled to each
other, respectively. When they are respectively coupled to each
other, the filter 18 can be taken up or rewound as the motor 31
rotates. Further, when the filter unit 17 is installed on the
filter device 30, the filter installation detection protrusion 29
activates the filter installation detection sensor 43. On the basis
of the state of the filter installation detection sensor 43, the
control unit 23 determines whether the filter is installed or
detached.
[0040] Hereinafter, operations of the filter device configured as
above will be described. When the control unit 23 causes the filter
take-up motor 31 to drive, the power is transmitted to the motor
power transmission gear 33 through the drive shaft 32. The power
transmitted to the motor power transmission gear 33 then is
transmitted to the next gear through the forward/reverse switching
gear 34. By controlling the forward/reverse switching gear 34
through the control unit 23, the position of the forward/reverse
switching gear 34 is changed and the take-up direction of the
filter 18 changes accordingly.
[0041] For taking up the filter in the normal direction of
rotation, power of the forward/reverse switching gear 34 is
transmitted to the normal rotation power transmission gears 35, 36
and to the normal rotation gear 37 to rotate the filter take-up
shaft 26. The filter 18 is fed from the filter feeding shaft 25 as
the filter take-up shaft 26 rotates. Similarly, for rewinding the
filter in the reverse direction of rotation, power of the
forward/reverse switching gear 34 is transmitted to the reverse
rotation power transmission gears 38, 39 and to the reverse
rotation gear 40 to rotate the filter feeding shaft 25. The filter
18 is fed from the filter take-up shaft 26 as the filter feeding
shaft 25 rotates. The rotation pulse detection rotary shaft 28 and
the rotation detection gear 41 rotate as the filter 18 is taken up.
The photosensor 42 detects the rotation of the rotation detection
gear 41 as a High and Low pulse signal and the control unit 23
obtains the detected pulse signal. Traveling of the filter 18 can
be detected on the basis of the detection signal from the
photosensor 42.
[0042] Now referring to FIG. 4, a control system of the filter
device in the projection type display apparatus will be described
in detail. FIG. 4 is a block diagram showing a configuration of a
control system 100 of the filter device.
[0043] The control system 100 is composed of each component of the
filter device 30 and a part of the control unit 23 for controlling
the entire projection type display apparatus. In the filter device
30, each of a filter winding driving unit 50, the filter 18, the
photosensor 42 and the filter installation detection sensor 43
constitutes a unit for control operation. The filter winding
driving unit 50 includes the various components shown in FIG. 3,
i.e., the motor 31 for driving the filter unit 17, the drive shaft
32, the motor power transmission gear 33, the forward/reverse
switching gear 34, and the gears 35 to 41. The filter 18, the
photosensor 42 and the filter installation detection sensor 43 are
as described with reference to FIGS. 1 to 3.
[0044] For example, the control unit 23 controls driving of the
motor of the filter winding driving unit 50 and processes
information from the filter device 30. In response to an
instruction from the control unit 23, the filter winding driving
unit 50 takes up or rewinds the filter 18 in the installed filter
unit 17 (not shown). The photosensor 42 generates pulses as the
filter 18 is taken up or rewound and supplies the pulses to the
control unit 23. The filter installation detection sensor 43
detects the presence or absence of the filter 18 (filter unit 17)
and supplies the result to the control unit 23.
[0045] When the filter installation detection sensor 43 detects
that the state of the filter is changed from absent to present, the
control unit 23 determines whether to carry out reset or not. In
this determination process, the filter winding driving unit 50
rewinds the filter 18 at a constant rotation speed. In so doing,
the photosensor 42 converts the rewound amount of the filter 18 to
a pulse signal and transmits the signal to the control unit 23. The
control unit 23 counts the number of Highs or Lows of the pulse
signal. When the pulse signal becomes undetectable within a
predetermined period of time, the control unit 23 determines that a
new filter 18 (filter unit 17) is installed and information on the
old filter 18 held in the control unit 23 is reset. The user may be
notified through a display unit (not shown) that the information
has been reset. When a predetermined number of pulses are detected
within the predetermined period of time, the control unit 23
determines that a used filter 18 is installed, and the filter 18 is
taken up by the same amount as the rewound amount.
[0046] Next, a description will be given of an exemplary flow of
determining whether to carry out the reset determination process or
not. FIG. 5 is a flowchart showing an exemplary operation of
detecting the installed state of the filter 18 (filter unit
17).
[0047] When the control unit 23 starts managing the installed state
of the filter 18, whether the filter 18 is installed or not is
determined at a predetermined cycle time through the filter
installation detection sensor 43 (step S1). The control unit 23
preferably obtains the information from the filter installation
detection sensor 43 over a plurality of times and determines that
the information is correct only when all of the pieces of
information obtained over a plurality of times match with each
other.
[0048] When the filter 18 is not installed (No), a filter
detachment flag is turned ON (S2) and the operation ends. The
control unit 23 may turn on a warning LED with the use of this flag
or may cause the display unit (not shown) to display a message.
[0049] When the filter 18 is installed (Yes), the value of the
filter detachment flag is referenced (S3). When the flag is ON
(Yes), in other words, when the filter 18 is reinstalled after once
being detached, the reset determination process in which whether to
reset filter information or not is determined is carried out (S4).
When the filter detachment flag is not ON (No), the operation ends
without carrying out the reset determination process (S4).
[0050] Next, the reset determination process (S4) shown in the
flowchart of FIG. 5, in other words, an exemplary flow of resetting
filter information automatically, will be described with reference
to FIG. 6. FIG. 6 is a flowchart showing an exemplary operation in
the reset determination process.
[0051] First, whether a predetermined amount of time has elapsed
from the installation of the filter 18 (filter unit 17) or not is
checked (step S10). If the predetermined amount of time has elapsed
(Yes), filter rewinding starts (S11). The reason that the rewinding
is not performed immediately is to prevent the hands and clothes of
a person who replaced the filter from becoming entangled.
[0052] As the rewinding starts, information from the photosensor 42
is checked regularly. And through a loop process of steps S12, S13
and S14, when pulse signals are sent from the photosensor 42, it is
determined that the filter is traveling and count-up is performed
(S14). That is, it is determined at step S12 whether or not a
predetermined number of counts has been exceeded, and if not (No),
it is determined whether or not the starting end of the filter 18
is detected (S13). If the starting end is not detected (No),
count-up is performed at step S14 and the operation returns to step
S12.
[0053] In the starting end detection at step S13, when no pulse is
sent from the photosensor 42 for a certain period of time, it means
that the traveling of the filter is stopped. Thus, it is determined
that the starting end is detected (S13). That is, the photosensor
42 and the control unit 23 form a starting end detection portion.
Any of other suitable configurations may be employed as the
starting end detection portion. However, since the rotation also
stops in the event of failure, it is necessary to distinguish
between a failure and starting end detection. For example, when no
pulse is sent, not even once, from the photosensor 42 from the
start of rewinding, it is determined as a failure.
[0054] When the starting end is detected at step S13 (Yes), the
rewinding is stopped (S15) and filter information is reset (S16).
Thereafter, the filter detachment flag is turned OFF (S20).
[0055] When the starting end cannot be detected at step S13 even
when the rewinding is carried out for a certain period of time, in
other words, when at the step S12 the predetermined number of
counts has been exceeded (Yes), take-up of the filter in the normal
direction starts (S17). When the take-up amount and the rewound
amount coincide with each other (S18), the take-up is stopped
(S19). Thereafter, the filter detachment flag is turned OFF
(S20).
[0056] In order to prevent a mistake in distinguishing between a
failure and starting end detection, it is also effective to confirm
with the user through the display unit (not shown) whether to reset
the information or not before performing the reset.
[0057] Although the present invention has been described on the
basis of its preferred embodiment, the configurations of the filter
device and the projection type display apparatus of the present
invention are not limited to those illustrated in the embodiment.
Configurations resulting from making a variety of modifications and
changes to the configurations illustrated in the embodiment are
also within the scope of the present invention.
[0058] As described above, the filter device according to the
present invention can automatically detect filter replacement and
reset filter information. Thus, it is useful as a filter device
that improves a projection type display apparatus in its user
maintainability.
[0059] The invention may be embodied in other forms without
departing from the spirit of essential characteristics thereof. The
embodiments disclosed in this application are to be considered in
all respects as illustrative and not limiting. The scope of the
invention is indicated by the appended claims rather than by the
foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are intended to be
embraced therein.
* * * * *